Power clamp



L. F. BLATT POWER CLAMP Sept. 20, 1966 2 Sheets-Sheet 1 Filed March 11,1964 INVENTQR. LELAND F. BLATT LLLI QM MM 4 0m ATTORNEYS Sept. 20, 1966L. F. BLATT 3,273,878

POWER CLAMP Filed March 11, 1964 2 Sheets-Sheet 2 INVENTOR.

LELAND F. BLATT (um ALMA 4" 6 m ATTORNEYS United States Patent 3,273,878POWER CLAMP Leland F. Blatt, Grosse Pointe Woods, Mich. (24121 MoundRoad, Warren, Mich.) Filed Mar. 11, 1964, Ser. No. 351,005 4 Claims.(Cl. 26932) This application relates to cylinder operated power clamps.

In my prior Patent No. 3,116,058, of December 31, 1963, I disclose acylinder operated power clamp wherein a carrier reciprocates in a tubeunder the influence of power means such as a power cylinder and pistonfor effecting movement of a clamp. As described in said patent, thecarrier fits tightly within the tube to provide an air cushion betweenthe carrier and the closed end of the tube with the clamp beingconnected to the open side of the carrier at the open side of the tube.

It is an object of the present invention to improve the constructiondisclosed in the foregoing patent by enlarging the cross-sectional areaof the carrier, and by reducing the friction between the carrier and thetube while at the same time preserving to a maximum extent the air tightfit between the carrier and the tube. This is accomplished in thepresent construction by forming the carrier of rectangular cross-sectioncomplementary to the rectangular cross-section of the interior of thetube and then providing frictionless rollers properly mounted betweenthe carrier and the tube so that while the air tight fit between thecarrier and the tube is maintained to a maximum extent, nevertheless thecarrier will reciprocate freely with-in the tube on the rollers and thusfriction is reduced.

Several diiferent embodiments of the foregoing have been disclosed inthe appended drawings which are confined to the details of constructionof the carrier and the tube per se, reference being had to thedisclosure of the aforesaid patent whose disclosure is hereintoincorporated by reference for a complete understanding of the clamps.

In these drawings:

FIG. 1 is an elevation view of the clamp.

FIG. 2 is a right end view.

FIG. 3 is an elevation view of one form of carrier, per sea FIG. 4 is aright end view of FIG. 3.

FIG. 5 discloses a modified form of carrier, per se, in side elevationview.

FIG. 6 is a right end view of FIG. 5 but showing tube parts as well.

FIG. 7 discloses another modified form of a carrier, per se, in sideelevation.

FIG. 8 is a right end view of the carrier of FIG. 7 with associated tubeparts also being shown.

As stated above, the invention hereof will best be understood uponreference to the disclosure of the aforesaid Patent No. 3,116,058 whosedisclosure is incorporated hereinto by reference.

The attached drawing discloses a support 11 which mounts the clamphereof, the latter including a clamping arm 16 which may be moved by themeans hereof for the purposes of clamping workpieces W-W' in relation toan anvil A and support 11.

The invention hereof relates to a power actuated means, mounted upon thesupport 11, for moving the clamp arm 16.

The mounting for the means includes a base 17 on said support formedwith a rectangular cross-section tube 22, the latter being unitary witha power cylinder 25 having a piston which may be air operated toreciprocate a rectangular cross-section carrier 35 within the tube 22.The connection between the piston of the power cylinder 25 and thecarrier 35 within the tube 22 is established 3,273,878 Patented Sept.20, 1966 through a tube rod 32 extending through a closed end 23 of thetube 22.

It will readily be understood that to those skilled in the art and asdescribed in said patent that when the tube rod 32 is reciprocated underthe influence of the piston in power cylinder 25, carrier 35 is likewisereciprocated.

Tube 22 has not only the closed end 23 but also an open end exposing theright end of the carrier 35 and enabling it to be connected by link 24through the open end -of the tube to the clamp arm 16, utilizing pivots26 and 27.

It is important to preserve the air tight fit between the rectangularcarrier 35 and the rectangular tube 22 to the maximum extent possibleand this can be accomplished simply by making carrier 35 in a form anddimension tightly fitting with-in tube 22. This, however, sets up theproblem of increased friction between carrier 35 and tube 22. To effecta balance and compromise between the desire for maximum air tight fitbetween the carrier and the tube and at the same time for minimumfriction between the carrier and tube, the arrangements of thisapplication have been developed and will now be described.

In each of the three modifications here shown, the carrier is ofrectangular cross-section conforming to the rectangular cross-section ofthe tube providing maximum pressure area and maximum air tight fitbetween the carrier and the tube.

In the form of FIGS. 1 to 4, the carrier 35 has its sides recessed tocontain friction reducing rollers 60 mounted on an axle 61 in across-bore of the carrier 35. These rollers 60 support and guide thecarrier in its reciprocal movement in tube 22 and reduce frictionbetween the carrier and the tube.

In FIGS. 5 and 6, the carrier 35 is provided with two roller chains 66and 67 on opposite sides of the carrier and embracing all four edges ofthe carrier for friction reducing.

In FIGS. 7 and 8, the four inner edges of the tube 22 are formed withhardened inserts or tracks 72 and two sets of roller bearings 73 areprovided between the four edges of the carrier 35 and the four tracks 72for friction reducing.

It will be observed that by forming the carrier and the tube ofcomplementary rectangular cross-section and by providing frictionproducing rollers in the manner herein disclosed, maximum pressure area,maximum air tight fit, and minimum friction between the carrier and theutbe are established.

Now having described the construction herein disclosed, reference shouldbe had to the claims which follow.

I claim:

1. A unitary clamping means including a horizontally arrangedrectangular cross-sectional tube having a closed end and an open end;

a tube rod in said tube passing through its closed end;

pneumatic means unitary with said tube and having a piston rod connectedto said tube rod for moving the tube rod along its axis and the axis ofthe tube;

a carrier secured to said tube rod adjacent the open end of the tube anddisposed in the tube for reciprocating movement therein;

a clamp;

means pivotally connecting the carrier to the clamp;

said carrier being of rectangular cross-section and substantiallycompletely filling said tube to provide an air cushion in said tube tothe side of said carrier between the carrier and the closed side of thetube; and

friction reducing guide rollers on and carried by said carrier enablingfrictionless reciprocation of said carrier in said tube.

2. Clamping means according to claim 1, wherein the rollers are largediameter rollers on opposite sides of the carrier and connected by anaxle in a cross-bore of the carrier.

3. Clamping means according to claim 1, wherein the rollers :are partsof two roller chains at opposite sides of and surrounding the carrier atits four edges and extending lengthwise of the carrier.

4. Clamping means according to claim 1, wherein the rollers are two setsof free roller bearings at opposite sides of the carrier and at its fouredges, and bearing tracks in the tube for the roller bearings at thefour edges of the carrier.

References Cited by the Examiner UNITED STATES PATENTS ROBERT C.RIORDON, Primary Examiner.

1. A UNITARY CLAMPING MEANS INCLUDING A HORIZONTALLY ARRANGEDRECTANGULAR CROSS-SECTIONAL TUBE HAVING A CLOSED END AND AN OPEN END; ATUBE ROD IN SAID TUBE PASSING THROUGH ITS CLOSED END; PNEUMATIC MEANSUNITARY WITH SAID TUBE AND HAVING A PISTON ROD CONNECTED TO SAID TUBEROD FOR MOVING THE TUBE ROD ALONG ITS AXIS AND THE AXIS OF THE TUBE; ACARRIER SECURED TO SAID TUBE ROD ADJACENT THE OPEN END OF THE TUBE ANDDISPOSED IN THE TUBE FOR RECIPROCATING MOVEMENT THEREIN; A CLAMP; SAIDPIVOTALLY CONNECTING THE CARRIER TO THE CLAMP; SAID CARRIER BEING OFRECTANGULAR CROSS-SECTION AND SUBSTANTIALLY COMPLETELY FILLING SAID TUBETO PROVIDE AN AIR CUSHION IN SAID TUBE TO THE SAID OF SAID CARRIERBETWEEN THE CARRIER AND THE CLOSED SIDE OF THE TUBE; AND FRICTIONREDUCING GUIDE ROLLERS ON AND CARRIED BY SAID CARRIER ENABLINGFRICTIONLESS RECIPROCATION OF SAID CARRIER IN SAID TUBE.